Source Audio SA170 Programmable EQ w/ 3 Cables +/- 18dB range over seven frequency bands. Four independent programmable user presets easily recalled via the Footswitch. Octave Extend Function: optimizes the EQ for bass with an additional freq band at 62Hz. 12dB of clean boost. Auto-scrolling function: automatically scrolls through all four presets to create unique and dramatic effects similar to sequencer or tremolo units.